Hematite, a form of iron
oxide, is one of the most abundant minerals on earth. Color ranges from black
to steel or silver-gray, brown to reddish brown, or red. It is harder than pure
iron, but much more brittle and it polishes to a high luster. The term hematite
is derived from the Greek word for blood, likely because powdered hematite is
reddish. Powdered hematite is used for chalk, paint pigments, and red rouge and
jewelers rouge polishing compounds. Natural hematite is a minor gem material used
to produce cabochons, beads, and small sculptures. It is only weakly magnetic.
What is called "magnetic hematite", which is often used in jewelry, is
a manufactured product that most often does not even contain hematite, but is
mainly synthetic ceramic barium-strontium ferrite magnet.